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For the second year in a row Ascochyta has hit lawns, athletic fields, and golf course turf. Ascochyta leaf blight is a grass fungus that causes a rapid straw to bleached appearance of the leaves primarily on Kentucky bluegrass and to a lesser extent on perennial ryegrass and tall fescue. The damaged lawns started showing up around the first of June and out breaks have been occurring all summer long. Some of the more severely damaged areas may require 3 or 4 weeks of good growing conditions to fully recover.

The damaged areas seem to occur very quickly; one day the grass appears fine and the next there is bleached tan grass everywhere and most noticeably where the mower tires track. In fact, to those unfamiliar with this problem they think that someone has damaged the lawn with a pesticide or fertilizer application. The Ascochyta related problems I am seeing have nothing to do with product applications. The fungus likes to grow during wet conditions favored by lots of rain or over irrigation. Infectious spores are everywhere throughout the lawn and with a sudden increase in hot temperatures they rapidly infect the stressed grass.

Tire tracks show up because the tires spread the spores and also cause just enough abrasion stress for the fungus to enter the plan tissue. Look for bleached leaf tips that are collapsed. It looks devastating because the top part of the plant is severely damaged but the crowns and lower stems are seldom killed. The attacks are so haphazard that it is impossible to give a good recommendation as to when to avoid mowing but in general raising the mowing height and mowing less frequently will reduce your chance of experiencing a mowing track incidence. It is interesting to note that Ascochyta blight in home lawns only occurs in full sun areas and it stops where the shaded lawn has less heat stress.

The damage at first appears very dramatic but the good news is to simply be patient because most of the damage is on the leaves while the crowns and roots of the plant are not damaged. As the plants continue to grow and after about a month of normal mowing the damaged leaf tips will be removed and the lawn will return to normal.
Normally we don’t recommend a preventative fungicide because it occurs too haphazardly and a curative fungicide doesn’t help after the leaf tissue is blighted. However, if you have experienced this in the same lawns and athletic fields for two years in a row you may want to consider a single preventative application of a fungicide next year from mid May to mid June.

Much of the turf I have sampled this summer has been confirmed to be Ascochyta by laboratory identification of spores. Like most of you old timers over the years I have observed tire tracking that we have assumed to be related to hot or dry conditions. Laboratory identification of the pathogen is the best way to determine if it was related to Ascochyta. Next year we will be conducting research with fungicides, moisture conditions, and wheel pressure to determine what is causing the tire tracking; is it Ascochyta or is it simply high temperature or low moisture stress. I think most of the blighting and wheel tracking we observed in June and July were associated with Ascochyta. To a lesser degree we may have also observed some wheel tracking from high temperature/drought stress.

Areas that have been severely injured can be recovered by dethatching, hollow tine aerification, and reseeding in September.

Here are some of the Ascochyta injured lawns that we have observed in Iowa during the summer of 2011.

Close up of Ascochyta symptoms on Kentucky bluegrass. Note the bleached leaf tips and banding of leaf blades. These symptoms are different from dollar spot that has leaf lesions with bleached centers and brown boarders.

Wheel track lawn injury from Ascochyta but notice that the tracks are not present in the shaded areas where the grass has less heat stress. The Ascochyta spores may be present everywhere but it usually requires a period of sudden heat or drought before symptoms appear. Picture taken 6/1711 Ames, IA.

Low maintenance (no fertilizer and no irrigation) Kentucky bluegrass along roadside showing mower tracks with Ascochyta injury. Even though high nitrogen can cause lush growth that increases infection in this case turf was injured in a low nitrogen situation.

Mowing tracks on golf course fairway. Injury occurred during a period when turf was not wilted or under low moisture stress. Grass died in lower wet areas but recovered on sloped areas. Also notice that the tracks stop at higher cut rough in front of sand trap. We will be conducting research next summer to discern what is Ascochyta related and what may be related to high temperature or drought stress wheel tracking. Picture taken 7-20-11 Waverly, IA.

We have been noticing some unusual areal shoots on what looks to be perennial ryegrass and we would like to hear from you if you have noticed anything like this at your facility. The pictures are from a football field in central Iowa. The field is a mixture of Kentucky bluegrass and perennial ryegrass that has been infiltrated with some patches of K-31 type tall fescue. Over the last three years it has been seeded with a mixture of Kentucky bluegrass and perennial ryegrass. The ryegrass component was made up of GLS (Grey Leaf Spot) type ryegrass and Tetraploid Turf-Type ryegrass. Our intent is to simply determine if others have observed this type of growth and if you consider it to be a positive or negative type of turf performance.

Please contact either myself or Andrew Hoiberg if you have seen anything like this:

Parts of the Midwest are getting hit with another round of snow but there is no denying that spring continues to inch closer by the day. In fact, before this last blast of winter weather, spring activities were slowly getting underway. Trees were beginning to break dormancy, bulbs were peaking through the soil, and lawns were starting to green up.

This process has already started across parts of the Midwest and some of you may have noticed patches, or areas of brown in your lawn. It’s typical to receive a number of questions from your clients about the cause of these brown spots during spring green-up. There are a number of reasons why these patches can appear and this article will address some of the most common reasons and discuss what action, if any, is needed to remedy the situation.

Dormant warm-season grasses
Most lawns in the upper Midwest contain cool-season grasses like Kentucky bluegrass, perennial ryegrass, and tall and fine fescues. Occasionally lawns, or parts of the lawn, will contain warm-season grass species. Examples of these could include zoysiagrass, buffalograss, or nimblewill. Whereas cool-season grasses grow best in the spring and fall, warm-season grasses prefer the mid-summer months and will remain dormant (brown) longer into the spring until warmer temperatures arrive.

If zoysiagrass or buffalograss are the cause of your brown spot there isn’t much you can do other than exercise patience until warmer weather arrives. Nimblewill can be selectively controlled with Tenacity herbicide. Tenacity herbicide will be made available to homeowners later this spring. Consult a lawn care professional for more information about Tenacity herbicide.

Dormant patches of nimblewill are very noticeable early in the spring. Nimblewill can be selectively controlled with Tenacity herbicide. Consult with a lawn care professional about the availability and use of Tenacity herbicide.

Warm-season grasses such as buffalograss are still brown while cool-season grasses such a fine fescues begin to green-up.

Leftover annual grassy weeds
Annual weeds such as crabgrass are always a concern and last year they seemed to be particularly troublesome. In lawns that had severe outbreaks, some of these annual grassy weeds may still be present. The good news is that you don’t have to worry about controlling leftover annual weeds. They have completed their lifecycle and are no longer alive. They did however drop seed and you may consider using a pre-emergence herbicide for the upcoming season.

Goosegrass, an annual grassy weed, is still present from the previous growing season.

Snow molds
Damage from pink and gray snow mold is most evident shortly after the snow melts. The grass will usually appear off-color and be matted down. Chemical applications to control snow molds in the spring are seldom recommended as most of the damage has already taken place. You can help your lawn by raking up the matted areas of grass with a leaf rake. Chances are there is some live turf hiding underneath. The picture below shows an area of gray snow mold on the Iowa State University central campus.

Gray snow mold on the Iowa State University campus.

Dog spots
Damage from animal urine will definitely create brown spots in the lawn. Where you can usually count on some recovery from snow mold damage, dog spots are very effective at killing grass. The best course of action is to remove the dead grass, break up the soil with a hand trowel or rake and re-seed the area. Note: Seed will not germinate and grow if a pre-emergence herbicide is to be used. The exception to this rule is when Tenacity or Siduron herbicides are used. Consult with a lawn care professional for more information about these products.

Man's best friend. Undoubtedly charming, but damaging to grasses.

Salt damage
De-icing materials that contain sodium can be quite harmful to turf. Brown patches or areas of turf along driveways, sidewalks, or streets could be caused from salt damage. Depending on the severity of damage, reseeding may be necessary. Aerification and watering (or rainfall) can help flush salts through the soil profile and improve the conditions of the site.

On Nov. 16, 2013 I wrote a blog about the fact that tall fescue seemed to be going off color earlier than usual in the fall of 2013. It seemed to be turning brown weeks ahead of the other cool-season species.

This spring, it seems to be greening up much later than usual. We had a hard winter in Ames and tall fescue is more susceptible to cold temperature damage than grasses like Kentucky bluegrass and creeping bentgrass. However, the greenup of tall fescue appears to be surprisingly late. The pictures below were taken on April 25, 2014. The demonstrate the very slow progress of greenup on tall fescue in our region.

The first picture is from the perennial ryegrass National Turfgrass Evaluation Program (NTEP) trial at the Iowa State turfgrass research area. The left is a tall fescue area surrounding the trial and the right is a series of 5 X 5 ft perennial ryegrass cultivar plantings. As I have covered in earlier blogs, perennial ryegrass also showed damage from the winter. Even the ryegrass is greening up well ahead of the tall fescue. The dormant plot is Lynn perennial ryegrass. There were considerable differences in greenup among the perennial ryes this spring. I have data that I will report later.

The next two pictures are the tall fescue NTEP trial. The green strip is a perennial ryegrass planted between the replications. The tall fescues have still not greened up as of today, April 30. We will be collecting data on tall fescue greenup as it begins.

The next two pictures are of a tall fescue sports field that I established at a local church site (the Plex) four years ago. The green area on the left in the upper picture and the right in the lower picture is a Kentucky bluegrass/perennial ryegrass turf that is emerging from dormancy. The right is the tall fescue field that is still brown on April 25,

I am wondering if others in the Midwest are seeing this same slow greenup of tall fescue. Send me some pictures if you are seeing this.

I have been experimenting with tall fescue in various situations. In the fall of 2012, following the serious drought that we had that year, I planted tall fescue in various parts of my lawn where I had lost Kentucky bluegrass during the drought. This included areas on my septic mound where the soil was thin and on an area above my buried propane tank.

I had mixed results with that experiment. We had another drought in 2013 that lasted from late June to October. I went a full 90 days without mowing non-irrigated areas. While some of the tall fescue did survive on the septic mound, some of it did not. On the thin soil over the propane tank, I lost the tall fescue late in the 2013 season. In a few other drought affected areas in my lawn, the tall fescue did survive the drought.

Tall fescue clearly stays green longer in droughts than does either Kentucky bluegrass or perennial ryegrass. The picture below was taken at the research station in August of 2013 during the peak of this year’s drought. The foreground is dormant Kentucky bluegrass. The tall fescue is in the background and it remained green through much of the drought.

In this picture, there is tall fescue surrounding our perennial ryegrass cultivar study. All of the ryegrass is nearly dormant, whereas the tall fescue around the outer edge of the trial remained green weeks longer.

I have also been noticing something else interesting about tall fescue late this fall. While seedling tall fescue has remained green well into the fall, mature tall fescue has gone off color earlier that either the Kentucky bluegrass or the perennial ryegrass at the research station. I have also noticed this on other mature tall fescue areas around Ames. HaS anyone else noticed the tall fescue going off-color earlier than usual this year?

The light brown area on the right is tall fescue and the green areas surrounding the tall fescue are Kentucky bluegrass.

I have had a couple of contacts on grass that was dormant seeded in the fall beginning to emerge in late March and early April.

The first one is from Rob Elder of Omaha Organics in Omaha. He seeded some areas in drought damaged areas in November of last year in Omaha. The picture below is from March 27. In this situation, they did not rake the area first, they just put the tall fescue seed on the bare areas and covered them with compost.

The second picture is from Larry Ginger of American Lawn care in Des Moines. The picture is from March 31 and shows emerging tall fescue.

Here is Larry's description of the process that he used.

Late August: Sprayed Roundup Pro at a 10% rate twice (2 days in a row) trying to kill exsisting wide-bladed tall fescue.

During the week of Thanksgiving, 2012:

Mowed the dead grass very short and dispersed the clippings to surrounding areas.

Applied grass seed.

Core aerated the areas 5 to 8 times.

Waited one day for the cores to dry up.

Then dragged the areas with a section of chain link fence.

Then crossed my fingers wondering if the dormant seeding would emerge in the spring.

I dormant seeded about 10,000 sqaure feet around our place, and most areas are not showing new seedlings yet. But it's very early, especially with the below normal March temperatures.

As many of you know, I have never been a very big fan of dormant seeding. I generally recommend that you keep the seed on the shelf until spring and seed when it is warm enough for germination. The reason for this is the high mortality rate of seed applied in the fall. While I am still concerned about dormant seeding of Kentucky bluegrass in the fall, I may change my mind on dormant seeding tall fescue into these damaged areas in lawns. We will see how these establishments go this spring.

Dr. Minner is planning a longer article for the blog on this subject in the next few weeks.

The ISU turf club did a major seeding project at Iowa State's Reiman Gardens this fall. There were areas of the bluegrass on top of the play mounds and along the lake that were either warn by traffic or thinned by the drought. They are trying turf-type tall fescue on these areas. The seeding took place on August 30. I have included some pictures of the seeded areas from November 17 showing the success that they had with establishment.

I'll watch this area through next season and let you know how the turf-type tall fescues are doing on the site.

Figures 1 and 2. Seeding around the lake on August 30. The area had been sprayed with Roundup a few days before seeding.

Figures 3 and 4. Seeding the top of the play mounds that get a lot of wear.

Figures 5 and 6. Areas are coming in well on November 11. The area around the lake is non-irrigated. It will be interesting to see how the mounds hold up next season.

Here is another post from Larry Ginger of "American Lawn Care" in Des Moines. Larry has been keeping us updated on late grub damage and fall seeding on lawns that he manages. Below are some pictures from Pleasant Hill, Ia showing active grubs on November 9. I am going to have to change my teaching notes on this. Generally the grubs have burrowed deep underground by this time, but here they are in November.

Larry also reports an 800% increase in his fall seeding business. He is using a three-way blend of Falcon IV, Five Point and Six Point turf-type tall fescues. He will send us some pictures of newly seeded lawns next week.

I have also been seeding areas that had been established to Kentucky bluegrass in the past, but were lost to the drought this summer. I have tried turf-type tall fescues as well in some areas and will report the success with this next season. My main concern is how well they will blend with the Kentucky bluegrass remaining on the area.

One of our major projects at the research station this fall is the national turfgrass evaluation (NTEP) tall fescue cultivar evaluation project. It includes 116 cultivars with most of the newest turf-types. The project was seeded on Sept 20. We had a lot of help from the ISU turf club. We have irrigation on the site and conditions have been perfect for germination. I have included pdf files of the cultivar list and the plot plan. If anyone would like to stop in and see the trial, feel free to come anytime 8 to 4 Monday through Friday.

Figure 1. Turf club members watering the newly seeded trial on Sept. 20